In the past, various kickboards have been available to help swimmers improve their swimming ability. One such kickboard is described in U.S. Pat. No. 3,945,068 to Carbonero. The kickboard described in that patent has an upturned forward end and a downturned rearward end. The forward end of the board is upturned for minimizing any tendency of the board to dive into the water caused by the downturned rearward end. A pair of flexible loops are secured to a top surface of the board. The loops are centrally located on the top surface and adapted for engagement of the hands of a swimmer during use of the board. In use, the swimmer's hands are inserted under the loops with the palms abutting the top surface of the board. The swimmer is then propelled in the water by kicking.
U.S. Pat. No. 4,518,364 to Jacobson discloses a flat kickboard. The kickboard is buoyant to float on water and has a bottom surface in contact with the water. A top surface of the board faces upwardly and away from the water and is adapted to receive a swimming instruction card. The purpose of providing the swimming instruction card is to permit the swimmer to review the individualized swimming instructions prior to a practice session.
When using the kickboard described by Jacobson, the swimmer is generally positioned immediately behind the board. In such a position, it may be difficult to perceive the writing on the swimming instruction card since the viewing angle is quite small. Accordingly, it is desirable to provide a message which is perceptible when viewed from a trailing edge of the kickboard.
One disadvantage of the prior art kickboards is that drag (resistance opposing the motion of the swimmer) of the kickboards cannot be varied. A primary purpose of a kickboard is to provide resistance to a swimmer, in order to strengthen the swimmer's legs while maintaining good body position. However, as the swimmer's ability improves, more resistance is needed so that the kickboard will actually benefit the swimmer in proportion to his ability. If a kickboard is designed for rehabilitating a patient or helping a beginning swimmer, it would not be very helpful in developing the muscles of a competitive swimmer since it does not have variable resistance. Since a competitive swimmer's strength is much greater than that of a beginner, a greater resistance is needed to further develop the competitive swimmer's muscles. However, even the ability and strength between two competitive swimmers may be quite diverse. Accordingly, to maintain maximum effectiveness, it is desirable to vary the drag of a kickboard to accomodate each swimmer's needs, whatever his ability and body type.
Another disadvantage of such prior art kickboards, is that the buoyancy of such kickboards is not variable. A kickboard that is highly buoyant may put the swimmer at an unnatural angle or posture when using the board. A kickboard which is not buoyant enough may provide too much drag for a beginning swimmer to tolerate. Additionally, an individual swimmer may need a different kickboard buoyancy for each different swimming stroke. For example, a buoyant board may be desirable when practicing a butterfly kick whereas a nonbuoyant board may be desirable for the same swimmer when practicing a breaststroke kick.
In a typical practice, a swimmer using a kickboard will kick a preselected distance and then rest a designated time interval. For example, a coach instructing a swim team may require each swimmer to kick 100 yards, rest for 30 seconds, and then kick another 100 yards, etc. Since a typical swim team has swimmers of diverse abilities; i.e., faster and slower swimmers, each swimmer will be kicking at different rates and, consequently, resting at different times. If the coach desires to talk to the swimmers while they are resting, he must talk to each swimmer individually since they are not all resting at the same time. This reduces the effectiveness of the coach as he cannot observe the swimmers who are swimming when he is instructing the swimmers who are resting. Accordingly, it is desirable to provide a kickboard which is capable of handicapping each swimmer such that they will all be kicking and/or resting simultaneously.